Bryan Boilers & 300 ユーザーズマニュアル

 

Date:  

8-4-2010 

 

Revision: 0 

 

Form:  

2396

 

 
LL CH DEMAND SWITCH: DISABLE, STAT, 
ENVIRONCOM REMOTE STAT  
The inputs that can function as the CH demand 
switch are: STAT, EnvironCOM Remote Stat. If 
the CH demand switch value is Disable, the LL 
master does not respond to CH demand. 
Warm Weather Shutdown  
WARM WEATHER SHUTDOWN ENABLE: 
DISABLE, SHUTDOWN AFTER DEMANDS  
 
HAVE ENDED, SHUTDOWN IMMEDIATELY 
WARM WEATHER SHUTDOWN SETPOINT:  
 
TEMPERATURE OR NONE 
When warm weather shutdown is Disabled then 
it has no effect (i.e. the Warm Weather 
Shutdown (WWSD) status shown on the priority 
diagram is false). 
 
These two parameters are shared by the stand-
alone Sola control and the LL master and have 
the same effect for either control. 
 
This function requires the outdoor temperature. 
This temperature may be obtained from either a 
local sensor or a LL slave. If WWSD is enabled 
but the outdoor temperature is invalid and 
unknown, then the WWSD function acts as if it is 
disabled and has no effect and an alert is issued 
indicating an invalid outdoor temperature. 
 
If it is enabled then it uses a 4°F (2.2°C) 
hysteresis: 
 
If WWSD is false, then when the Outdoor 
temperature is above the value provided by 
Warm weather shutdown setpoint 

then: 

 
If "Shutdown after demands have ended" is 
selected then any current CH demand that is 
present prevents WWSD from becoming true; 
that is if CH demand is false then WWSD 
becomes true. 
 
Otherwise if "Shutdown immediately" is 
selected then WWSD becomes true, it 
immediatetly causes CH demand to end. 
 
If WWSD is true, then when the Outdoor 
temperature is below the value provided by 
Warm weather shutdown setpoint 

minus 4°F 

(2.2°C) then WWSD becomes false. 
 
When warm weather shutdown is true then:  
 

New occurrences of CH demand is inhibited. 
DHW demand is not affected. 
 
Frost protection  
 
LL master frost protection is enabled with Frost 
protection enable: Disable, Enable 
 
The need for frost protection is actually detected 
independently by each slave which notifies the 
master whether frost detection occurred in CH 
frost detection, and/or its DHW frost detection, 
and whether it is severe enough to require 
burner firing as well as pump operation. This is 
done via its Slave status parameter. 
 
If  Frost protection enable is Enable then the 
master's Slave write message, will indicate CH 
or DHW frost protection or both as read from 
each slave's Slave Status. This will cause any 
slave pumps which are enabled to follow this 
status to turn on without any other action 
required from the master. 
 
If any slave is indicating CH or DHW frost 
protection, and additionally that slave's Slave 
status 

register indicates burner firing is 

requested then the LL master's frost protection 
burner demand will be true. 
 
If the priority scheme allows the master to honor 
this demand, then it will fire a single burner (the 
current lead burner as specified by the 
sequencer) at the rate indicated by Frost 
protection rate: 0-100%. 

(100% represents 

100% firing of this boiler, and where 0% or any 
value less than the boiler's minimum firing rate 
represents the minimum firing rate).  
 
Priority Control  
 
CH heat demand is a simple signal such as 
STAT, Enviro- COM remote stat, or Warm 
Weather Shutdown. 
 
Frost protection input to the priority logic is not a 
heat demand, it is a burner demand (because 
frost protection always turns on pumps without 
regard to the priority control - it is a priority item 
only if it also wants to fire). 
 
Master Status  
 
MASTER HEAT DEMAND  
 
Is a data item which contains the status for the 

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